This invention relates to a pouring vessel made of synthetic resins, which has been obtained by laminating an inner container capable of being deflated and a squeezable outer container in a peelable manner, so as to enable the content to be discharged and used repeatedly without sucking up outside air into the inner container.
Utility models laid open No. 1982-44063 and No. 1995-22951 describe prior-art pouring vessels of the squeezable type, which comprise an inner container and an outer container in which to put the inner container.
The prior art described in utility model laid open No. 1982-44063 refers to a pouring vessel comprising an inner container and an outer squeezable container having an air hole at the bottom. Mayonnaise is discharged from the inner container by squeezing the outer container. Then, outside air is introduced into the void between the outer container and the inner container. At that time, the inner container maintains its deformed shape, while the outer container returns to the original shape because of its restoring force.
The prior art described in utility model laid open No. 1995-22951 refers to another pouring vessel comprising an inner container and an outer squeezable container combined and fitted to each other. The inner container is provided with the first check valve that permits the content to pass through the valve and come out of the inner container but does not permit outside air to enter the inner container. The outer container is provided with the second check valve that permits outside air to enter the void between both containers, but does not permit air to escape from the void.
The method of utilizing a pair of adhesive resin strips is also generally in use. These adhesive resin strips adhere and fix the outer container and the inner container to each other over the entire height of the containers and keep the deflationary deformation of the inner container at a certain shape that gives no shrinkage in the height direction, thereby ensuring the flow path for the content and making the discharging operation smooth.
In order for the adhesive resin strips such as described above to fulfill their function, a simple and effective method is to dispose the pair of adhesive resin strips at axisymmetric positions on the central axis of the body. But there arises a problem here concerning their width. If the width is too wide, the inner container cannot be deflated fully. If the width is too narrow, the content flow path is blocked because of deflationary deformation that takes place in an early period of discharge. As a result, no smooth discharging operation is obtained, and thus, a significant amount of content is left unused in the inner container.
This invention has been made to solve such a problem found in prior art. The object of this invention is thus to provide a pouring vessel of the squeezable type that has a high discharging ability and is capable of minimizing the remaining volume of the content.
From a design point of view, the bodies of many containers now in use have an elliptical cross-section rather than the circular one. An important point in this case is where the adhesive resin strips are positioned. If a pair of adhesive resin strips is disposed at both ends of assumed long axis, axisymmetrically on the central axis of the body, then deflationary deformation proceeds almost symmetrically in the unadhering portions of the inner container divided into two portions by the adhesive resin strips. Stable discharge operation can be secured under this arrangement.
However, even though the adhesive resin strips are disposed at the above-described positions in the cross-section of the body having an elliptical shape rather than a circular one, there arises a problem concerning their width. If the adhesive resin strips have too wide a width to ensure a flow path for the content, any deformable portion disappears under the condition that the inner container has deformed to a considerable extent due to the decrease in the volume of the content. Eventually, both ends of each adhesive resin strip resist the pressure caused by the squeeze. In this state, further discharge becomes difficult in spite of a significant volume of the content remaining in the inner container.
This invention also has been made to solve such a problem found in prior art. Another object of this invention is thus to provide a pouring vessel of the squeezable type having an elliptical shape, which can be smoothly squeezed to the last moment of the discharging operation and is capable of minimizing the remaining volume of the content.
Among the means of solving the above-described technical problem, the means of carrying out the invention of claim 1 has the following configuration. The pouring vessel comprises:
a blow-molded, bottle-like container consisting of an outer shell layer and an inner layer, which are peelably laminated together, and having a body of a cross-sectional shape in which an assumed symmetrical long axis and a symmetrical short axis are orthogonal with each other, said outer shell layer forming an outer container, which has the flexibility to make this container squeezable and recoverable to its original shape, and said inner layer forming an inner container for receiving its content inside and capable of being deflated and deformed inward with the decrease in inner pressure; and
a discharge cap having an opening and attached to neck of the container.
In this configuration, a pair of adhesive resin strips is formed at both ends of the long axis of the body, axisymmetrically on the central axis, by adhering the outer shell layer and the inner layer over the roughly entire height of the container, and the width (La) of this adhesive resin strips is set in the range of 0.8(xc2xc)(Lxe2x88x922D1) to 1.2(xc2xc)(Lxe2x88x922D1), preferably at (xc2xc)(Lxe2x88x922D1), wherein D1 is the length of the long axis in the cross-section of the body (2); and L is the peripheral length in the cross-section of the body.
The discharge cap is provided with the first check valve mechanism that prevents the back flow of the content from the opening to the inner container and also prevents the inflow of outside air. The outer container is equipped with an outside air introduction mechanism for introducing outside air into the interlaminar void between the outer shell layer and the inner layer, with the outside air introduction mechanism being connected to the second check valve mechanism, which has a function to confine air within the void at the time of squeeze.
In the invention of claim 1, the pouring vessel is squeezed to discharge the content. When the squeeze is stopped and the pressure is released, the outer container begins restoring its original shape because of its resilient, restoring force. At the same time, the first check valve mechanism provided in the discharge cap is in action to stop the discharge of the content and to prevent the back flow of the content and the inflow of outside air into the inner container. Since the inner container remains deformed with the decrease in the volume of content, outside air is introduced into the void between the outer shell layer and the inner layer through the air introduction mechanism, and the outer container is restored to its original shape.
If the pouring vessel is squeezed again in the state in which the outer container has been restored to its original shape, air in the void is pressurized by the squeeze because the second check valve mechanism seals the void. Thus, a pressure is applied on the inner container to discharge the content further.
Since the first check valve mechanism prevents the inflow of outside air into the inner container, there is no airspace in the inner container. The content is thus always located in front of the opening. No matter what position the pouring vessel takes when it is used, the content can be discharged easily. It is also possible to prevent the content from being decomposed or deteriorated caused by air oxidation.
With the formation of vertical adhesive resin strips, a pair of unadhering portions of the inner layer (hereinafter referred to as unadhering inner layers) is also formed. As the pouring vessel is squeezed and the content is discharged, these unadhering inner layers are deformed. This deformation proceeds in the following manner. When the deformation is observed on the cross-section of the body in the drawing having the vertical long axis, the right and left unadhering inner layers deform first at their central portion in the flattening direction. As the deformation further proceeds, the right and left unadhering inner layers come in contact with each other roughly on the long axis. This portion of contact extends toward the adhesive resin strips disposed at both ends of the long axis. Ideally, the inner container is deflated axisymmetrically on both of the long and short axes.
As the content is further discharged, the inner container continues its deflationary deformation until there remains little content in the inner container. At that time, the portion of contact extends over the entire long axis, and the inner container is almost completely in a flat state on the cross-section. If under this condition, the length of the unadhering inner layers is set at a sum of the length of the long axis and the width of each adhesive resin strip on the cross-section of the body, or more specifically, if the width of each adhesive resin strip is set at a length equal to (xc2xc)(Lxe2x88x922D1), then the inner container becomes almost completely flat as soon as discharge of the content is completed.
However, depending on the condition of use, the unadhering inner layers are not deflated axisymmetrically on both the long and short axes, but something asymmetric or partially loose may occur, and deflationary deformation cannot lead the inner container to become completely flat. In such a case, it is preferred to set the width of the adhesive resin strips at a value slightly less than (xc2xc)(Lxe2x88x922D1).
If the content has high viscosity, it may be preferred in some cases to set the width of the adhesive resin strips at a value slightly wider than (xc2xc)(Lxe2x88x922D1) so as to secure a larger flow path than usual and to maintain a smooth content-discharging operation.
Various tests were conducted under the above-described conditions and for the purposes of use. It has been found that a width in the range of 0.8(xc2xc)(Lxe2x88x922D1) to 1.2(xc2xc)(Lxe2x88x922D1) gives good results that only quite a small amount of the content remains in the inner container after the use and that the discharging operation can be smooth to the last moment of squeeze.
If the width of the adhesive resin strips is set at a value wider than 1.2(xc2xc)(Lxe2x88x922D1), the deformable portion practically disappears in the state in which a fair amount of the content has remained still in the inner container, because of a dimensional limitation on the cross-sectional length of the unadhering inner layers. In this case, the unadhering inner layers on both sides of the adhesive resin strips are so stretched at four ends of the adhesive resin strips in the width direction (hereinafter referred to as strip ends) that it is difficult to deflate and deform these layers any more. In this state, no matter how the outer container is squeezed, it is hard to discharge the content.
If the width of the adhesive resin strips is set at a value narrower than 0.8(xc2xc)(Lxe2x88x922D1), the unadhering inner layers have a larger cross-sectional length than necessary. Even if a considerable amount of content still remains in the entire inner container, there is a fear that the cross-sectional shape of the inner container almost blocks the flow path at a place where the content tends to get smaller, depending on the conditions of discharge from, or of storage in, the vessel. In this state, smooth discharge of the content is no longer possible.
The means of carrying out the invention of claim 2 exists in the configuration that, in the invention of claim 1, the body has a circular cross-section in which the length of the long axis is made equal to that of the short axis.
Due to the configuration of claim 2, the residual amount of the content can be reduced in the vessel having the body of a circular cross-section, while steadily maintaining favorable discharging operation. It is also possible to discharge more content in a single squeeze from the vessel with a circular cross-section than from the vessel with an elliptical cross-section, because each stroke of squeeze deformation can be enlarged for discharging the content.
The means of carrying out the invention of claim 3 has the following configuration. The pouring vessel comprises:
a blow-molded, bottle-like container consisting of an outer shell layer and an inner layer, which are peelably laminated together, and having a body of a cross-sectional shape in which an assumed symmetrical long axis and a symmetrical short axis are orthogonal with each other, said body comprising an outer shell layer that forms an outer container, which has the flexibility to make this container squeezable and recoverable to its original shape, and said body also comprising an inner layer that forms an inner container for receiving its content inside and capable of being deflated and deformed inward with the decrease in inner pressure; and
a discharge cap having an opening and attached to neck of the container.
In this configuration, a pair of adhesive resin strips is formed at both ends of the long axis of the body, axisymmetrically on the central axis, by adhering the outer shell layer and the inner layer over the roughly entire height of the container, with each strip being divided by the long axis into right and left parts having different lengths in the width direction.
The discharge cap is provided at the opening with the first check valve mechanism that prevents the back flow of the content to the inner container and also prevents the inflow of outside air. The outer container is equipped with an outside air introduction mechanism for introducing outside air into the interlaminar void between the outer shell layer and the inner layer, with the outside air introduction mechanism being connected to the second check valve mechanism, which has a function to confine air within the void at the time of squeeze.
In the invention of claim 3, the pouring vessel is squeezed to discharge the content. When the squeeze is stopped and the pressure onto the body is released, the outer container begins restoring its original shape because of its resilient, restoring force. At the same time, the first check valve mechanism provided in the discharge cap is in action to stop the discharge of the content and to prevent the back flow of the content and the inflow of outside air into the inner container. Since the inner container remains deformed with the decrease in the volume of content, outside air is introduced into the void between the outer shell layer and the inner layer through the air introduction mechanism, and the outer container is restored to its original shape.
If the pouring vessel is squeezed again in the state in which the outer container has been restored to its original shape, air in the void is pressurized by the squeeze because the second check valve mechanism seals the void. Thus, a pressure is applied on the inner container to discharge the content further.
Since the first check valve mechanism prevents the inflow of outside air into the inner container, there is no airspace in the inner container. The content is thus always located in front of the opening. No matter what position the pouring vessel takes when it is used, the content can be discharged easily. It is also possible to prevent the content from being decomposed or deteriorated caused by air oxidation.
With the formation of vertical adhesive resin strips, a pair of unadhering inner layers is also formed. As the pouring vessel is squeezed and the content is discharged, these unadhering inner layers are deformed. This deformation proceeds in the following manner. When the deformation is observed on the cross-section of the body in the drawing having the vertical long axis, the right and left unadhering inner layers depressingly deform first at their central portions. As the deformation further proceeds, the right and left unadhering inner layers come in contact with, and push themselves against, each other roughly on the long axis. The deflationary deformation proceeds in such a way that this portion of contact extends toward the adhesive resin strips disposed at both ends of the long axis.
As the content is further discharged and deflationary deformation goes on, the deformable portion practically disappears because of a dimensional limitation on the cross-sectional length of the unadhering inner layers. If the right and left parts of the adhesive resin strips divided by the long axis have the same width, the inner container to be deflated is born at four strip ends of these adhesive resin strips so that it is difficult to deflate and deform the unadhering inner layers any more. In this state, no matter how the outer container is squeezed, it is hard to discharge the content.
In this invention, however, the right and left parts divided by the long axis have different lengths in the width direction. Even if the deflationary deformation proceeds in the same way, the shorter part of each adhesive resin strip allows for more deflationary deformation than the longer part does. Therefore, these strip ends put no obstacle in the process of deflationary deformation.
Near the ends of longer parts of the adhesive resin strips divided in two parts by the long axis, the deformable portion practically disappears because of a dimensional limitation on the cross-sectional length of the unadhering inner layers. The pressure caused by the squeeze is held at these ends. On the other hand, there still is dimensional extra space near the ends of the shorter parts of the adhesive resin strips. The content can be discharged until no deflationary deformation is possible on the sides of the shorter parts of the adhesive resin strips. Thus, the remaining content can be minimized to a large extent.
The means of carrying out the invention of claim 4 exists in the configuration that, in the invention of claim 3, the body has an elliptic cross-section.
As the cross-sectional shapes in which the assumed symmetrical long axis and the symmetrical short axis are orthogonal with each other, there are ellipse, ellipsoid, and flat diamond. In the case of an elliptic shape, the diameter changes gradually from the direction of long axis to the direction of short axis, without giving any bending point to the circumference. It is possible, therefore, to proceed with the deflationary deformation of the unadhering inner layers much more stably and to blow-mold the inner container easily.
Means of carrying out the invention of claim 5 includes the invention of claim 3 or 4, and also comprises that each adhesive resin strip is divided by the long axis into the right and left parts, which have widths at a ratio in the range of 10:1 to 10:6.
The above configuration of claim 5 allows for most efficient discharge operations and minimizes the remaining volume of content. If this ratio of right to left part came close to the symmetrical state, or if the ratio were at 10:6 or more, then the effect of asymmetry would not work remarkably. If the ratio were 10:1 or less, the deflationary deformation of the unadhering inner layers would not go on smoothly.